Apparatus for the manufacture of steel reinforcing bar for concrete structures and the like



May 27, 1952 2,598,039

E FAZl APPARATUS FOR THE MANUFACTURE OF STEEL REINFORCING BAR FOR CONCRETE STRUCTURES AND THE LIKE Filed March 1, 1949 3 Sheets-Sheet l INVENTOR Fz/L w 0551.21

A ORNEY May 27, 1952 F. DE FAZ! 2,598,039

APPARATUS FOR THE MANUFACTURE OF STEEL REINFORCING BAR FOR CONCRETE STRUCTURES AND THE LIKE Filed-March l, 1949 3 Sheets-Sheet 2 INVENTOR 75 FuLv/0 DEI'ZZ/ ATT NEY 2,598,039 FORCING STRUCTURES AND THE LIKE F. DE FAZl FOR THE MANUFACTURE OF STEEL REIN FOR CONCRETE 3 Sheets-Sheet May 27, 19 5 Filed Mar 1 j FULV/ODffilZ/ A ORNEY Patented May 27, 1952 APPARATUS FOR THE MANUFACTURE OF STEEL REINFORCING BAR FOR CON- CRETE STRUOTURES AND THE LIKE Fulvio De Fazi, Bronx, N. Y., assignor to Wcbrib Steel Corporation, New York, N. Y., a corporation of New York Application March 1, 1949, Serial No. 78,904

4 Claims. 1

The invention relates to apparatus for the manufacture of steel reinforcing bar for concrete structures, and the like, and particularly to apparatus for producing transverse grooves within the circumferential grooves of a bar mill roll. It has special reference to the manufacture of bar of the type disclosed in the Stites patent, No. 2,405,274, granted August 6, 1946, but is applicable also to the manufacture of bars of other kinds and for other purposes.

In the manufacture of steel reinforcing bar for concrete, many problems have been presented, and some of these have been so serious as to require making compromises between what is best in structural concrete reinforcing bar design, and what is best from the standpoint of rolling mill practice. The reinforcing bar engineer works out a theoretical ideal design of bar, and then the rolling mill engineer asserts that a bar of that design is one which it is not practicable to manufacture commercially. This difficulty has been encountered in connection with attempts to roll deformed bar wherever that bar has projecting ribs, or lugs, extending in a direction which, generally speaking, is opposed to the long axis of the bar, 1. e., lugs extending substantially transversely of the bar. Part of the difficulty lies in machining the transverse indentations, or grooves, in the rolls which are to form the transversely ribbed bar. For one thing, these are grooves within grooves, because first we have the circumferential grooves which form the body of the bar, and within these circumferential grooves are the transverse grooves which form the ribs. The transverse grooves generally areformed on a milling machine, and the milling tool must operate within the. narrow confines of the circumferential grooves in the roll. This means that the milling cutter 'must be carried by a relatively long shaft of small diameter, resulting in frequent tool breakage.

The problem is particularly acute when it comes to the manufacture of bar in the smaller sizes. Untold difliculties have been experienced, for example, in attempts to form the transverse grooves in rolls for the production of bar of small cross section according to the aforesaid Stites patent, No. 2,405,274; particularly so in the sizes known to the trade as W1, W2, and W3.

Size W1 has a major axis dimension of less than inch, and the transverse grooves in the rolls for the production. of this bar are small and are spaced very' close together. Also, the

circumferential grooves within v which the milling cutter must operate in shaping the transverse grooves are themselves very small (approximately 0.2 inch wide), which means that the cutter shaft must be very long and slim. The resulting tool breakage is of such frequency as to unduly increase the initial and replacement cost of the rolls, this being reflected in the cost of producing the small sizes of reinforcing bar. On a tonnage price basis, the cost of the smaller sizes of bar is necessarily higher than for the larger sizes even Without taking into account the factor of tool breakage, so it will be appreoiated that the problem here outlined is a serious one and of great practical effect.

It has been the primary object of my invention to find a solution to this problem of tool breakage.

Also, a general object of the invention is to provide improvements in apparatus for the manufacture of steel reinforcing bar for concrete, and particularly in apparatus for producing transverse grooves within the circumferential grooves of a bar mill roll, whereby the cost of manufacture is reduced and the machining operations on the roll are simplified and take less time to perform.

Other objects and advantages of my invention will appear as the description proceeds.

In accordance with my invention in apparatus for the manufacture of reinforcing bar for concrete structures and the like, there is provided a machine unit for producing transverse grooves within the circumferential grooves of a bar roll-' ing mill roll, this unit comprising a cutter shaft and a supporting bearing member therefor, the bearing member having a recess therein of generally arcuate form to conform substantially to the circumference of the rolling mill'roll, and cutting teeth on the shaft, the shaft being positioned in the bearing member adjacent the aforesaid recess to expose the cutting teeth for operation on the roll. The bearing member is arranged to support the shaft at points closely adjacent the cutting teeth. The bearing member preferably comprises separable. parts with portions of the shaft bearing formed in each part to allow assembly with the shaft without removal of the cutter, and so that cutting teeth formed integrally withthe shaft can be employed.

Referring to the drawings, in which certain preferred embodiments of the invention are shown:

Figs. 1 and 2 illustrate my preferred form of apparatus as designed for use in conjunction with a conventional milling machine. Fig. 1 is a front elevational view and Fig. 2 an end elevational view.

Figs. 3 to 6 inclusive are enlarged. crosssectional views of various portions of the same apparatus as follows: Fig. 3 is a detail view in vertical section taken transversely of the milling attachment on the line 3-3 of Fig. 2; Fig. 4 is a detail view in vertical cross-section taken on the line 4-4 of Fig. 3; Figs. 5 and 6 are detail views in vertical cross-section taken on lines 55 and 65 of Fig. 2 respectively; Figs. '2 and 8 illustrate a modified construction of apparatus for producing transverse grooves within the circumferential grooves of a bar rolling mill roll in which the bearing member for the cutter shaft has adjustable elements; Fig. 7 is a side elevational view, and Fig. 8 a vertical cross-sectional view taken on the line 8-3 of Fig. '7.

Figs. 9 to 15 inclusive illustrate successive steps in making a bar mill roll for the manufacture of steel reinforcing bar, to which the apparatus shown in Figs. 1 to 3 inclusive is applicable. Thus: Fig. 9 is a side elevational, or face, View of a bar mill roll in which have been machined a number of pairs of circumferential grooves ready to be machined further with the use of my novel apparatus. Fig. 10 is an enlarged detail cross-sectional view taken on the line '|0Hl of Fig. 9, illustrating one of the pairs of circumferential grooves. Fig. 11 is a somewhat schematic view similar to Fig. 10 but showing transverse grooves formed in the circumferential grooves of the roll in. accordance with one manner of employing my invention. (In this view it is assumed (I) either that the transverse grooves of each pair are. directly opposite one another, or (2) that the cross-section has been taken in such a manner as to make them appear so in this view.) Fig. 12 is a detail View similar to Fig. 10 but illustrating a further preparatory machining step according to another procedure which can be followed. Fig. 13 is a view similar to Fig. 12 showing transverse grooves formed in the circumferential grooves I transversely of the roll but longitudinally with respect to the direction of the circumferential grooves, and to the transverse grooves therein. Fig. 15 is a further detail view taken as indicated at |5 -|5 in Fig. 14. It is a development, in a flat plane, of a portion of the surface of the roll upon completion of the operations which involve the use of my apparatus.

Referring to Figs. 1 and 2, the apparatus comprises, in its general arrangement, a machine unit H; for producing transverse grooves within circumferential grooves H of a bar rolling mill roll R, the unit comprising a cutter shaft 18 and a supporting bearing member l9 therefor, the bearing member having a recess 28 therein of generally arcuate form to conform substan The machine unit i6 is mounted in such a manner as to permit it to be moved radially with respect to the surface of roll R, with cutter shaft [8 in line with grooves 11. Also, suitable means are provided for driving shaft I8. In the preferred construction illustrated, the unit is made in the form of an attachment which can be mounted directly on the overarm 22 of a con ventional milling machine. Roll R, which is to be machined, is supported on centers 23 associated with the headand tail-stock assemblies of the machine. A bracket 24 having a split sleeve portion 25 is secured on overarm 22 by clamping screws 26. A flanged guide plate 21, secured to a vertical surface of bracket 24, furnishes a base for a vertically movable slide 28 having lateral flanges 29 embracing the raised central portion 30 of guide plate 21. Bearing member l9, which in mypreferred construction comprises separable parts in the form of plates 3i, 32, is secured to slide 28 as by means of screws 33. A feeding screw 34 having athreaded engagement with slide 28, or with a collar or nut attached thereto by means of screw 35, provides means for raising and lowering the slide and its associated machine unit comprising the cutter shaft and bearing member. Feeding screw 34 passes through an opening in the raised portion 39 of guide plate 21, being freely rotatable with respect to the guide plate, but suitably held against endwise movement with respect thereto. Hand wheel 36, with operating handle 33, is fixed to feeding screw 34, and the operation of this hand wheel will raise and lower slide 28 in a manner which is similar in operation to the conventional slide operating mechanisms for advancing and retracting the tools of milling machines, lathes and other similar apparatus well known in the art. If desired, a graduated index wheel or element 38 fixed to hand wheel may be provided for cooperation with an index marking 39 on guide plate 21, so that the operator will have a guide to indicate the extent of the advance of the cutter 21 into the Work.

The meeting faces of plate 3| of bearing member 19 and slide 28 are provided with complementary recesses for apositioning key 4|) (Figs. 1 and 5). The meeting faces of plates 3| and 32 are provided with complementary recesses to receive cutter shaft l8, so that portions of the shaft hearing are formed in each part 3| and 32 of bearing member IS. The shaft bearing recesses are counterbored to receive a driving spindle 4|, the inner end of which is recessed as at 42 to receive an enlarged end of shaft l8 keyed to the spindle 4|, as at 43, or otherwise connected so that the spindle will drive the shaft. Plates 3| and 32 are also recessed as at 44 to allow clearance for cutting teeth 2|, and these plates are slotted at 45 to receive a key 48 entering a circumferential groove which forms a reduced portion 41 of spindle 4| to hold the spindle against endwise movement. Shaft I8 itself is further restrained against endwise movement by an enlarged end 48 received in a counterborc at the end of plates 3| and 32.

Plates 3| and 32 are aligned by means of dowel pins 49 passing through aligned apertures in the plates. In assembling the bearing member 19 and cutter shaft l8, plates 3| .and 32 are separated, and the shaft l8 with its'spindle 4| is inserted, plates 3| and 32 then being brought togetherand fastened as by means of screws 50. Key 46 is inserted in slot 45 and held in place by means of a set screw 5|.

Spindle 4| is driven in any suitable manner.

In my preferred construction as shown, a pulley 52 fixed to the spindle is driven by a belt 53 from a pulley 54 carried by'a 'shaft55 mounted in a bore in slide 28. Mounted on this same shaft 55 for rotation with pulley 54 is a pulley 5B driven by a belt 51 from pulley 58 fixed to the shaft of a motor 59 suitably mounted on'bracket 24.

Shaft 55 is eccentrically mounted with respect to the supporting part 60 thereof, the latter being clamped in an adjusted position by means of screws 61 passing through flanges 62 defining a split portion of the bore of slide 28 which receives said portion 6!! of the shaft. By loosening screws Bl, shaft 60 can be turned so as to move shaft 55 toward or away from spindle 4| to vary the distance therebetween and thereby adjust the tension in belt 53. By adjusting this tension in order to allow slippage of the belt over the pulleys, the cutter shaft can stop rotating in the event hard spots are encountered in the metal of the roll R.

during cutting of the transverse grooves in the circumferential grooves ll thereof.

I shall now describe the operations performed by the apparatus disclosed, referring particularly to Figs. 9 to 15 inclusive which illustrate successive steps in making a bar mill roll for the manufacture of steel reinforcing bar. In Fig. 9 we see a side elevational View of such a bar mill roll R in which have been machined, as by a conventional lathe operation, a number of pairs of circumferential grooves ll. R011 R is mounted on centers 23 associated with the headand tailstock assemblies of the machine. Inasmuch as transverse grooves are to be cut at spaced intervals in the circumferential grooves, it is desirable to have suitable indexing mechanism for adjusting the position of the roll after each groove is cut in its turn. The indexing mechanism may comprise a part of the head-stock assembly as found in conventional milling machines. Fig. 10 shows a detail in cross-section of one of the pairs of circumferential grooves I1. According to what I now consider the preferred procedure, the edges of grooves I! are further machined to form rounded portions 63 (Fig. 12) and also to form the rounded center portion 64 between each pair of grooves. These further machining steps can be performed in any conventional manner with the use of standard lathe or grinder equipment, or otherwise, and it will be understood that these steps form no part of the present invention, but depend upon the form of bar which it is desired to produce. After the completion of these preliminary machining operations, and with roll R fixed in position adjacent the cutting assembly as indicated in Figs. 1 and 2, the cutter is advanced from a position somewhat elevated from that shown, with the power on and cutter rotating. Hand wheel 36 is operated in a direction to produce this advancing action of the cutter. Each time this operation is performed, one of the transverse grooves 65 is formed as illustrated in Fig. 13. Then the hand wheel 36 is backed off, the roll R re-indexed to the next position, after which the operation is repeated as before. This is continued until transverse grooves 65 have been formed at spaced intervals entirely around the circumference of one of the grooves l1.

Then the table of the milling machine is shifted by an amount sufficient to align the cutting head with the next one of the circumferential grooves I! in which are to be cut the transverse grooves 65. If desired, two or more cutter assemblies can be mounted side by side so as to cut the transverse grooves in two or more of the circumferential grooves I1 simultaneously. If, however, the transverse grooves which are to be formed in one pair of circumferential grooves are offset from one another as indicated in Fig. 15, it would be desirable to cut the transverse grooves separately in each one of the circumferential grooves, although another possibility would be to mount say two cutter shafts-at intervals so spaced as to cut one groove in each of two adjacent pairs simultaneously. Then the roll would be shifted longitudinally and the transverse grooves cut in the other circumferential groove of each pair. In this way the center of the cutter can always be kept in alignment with the center of the roll so as to approach the roll in a true radial direction.

According to an alternative procedure, after formation of grooves I! in the form shown in Fig. 10, the transverse grooves are then cut to produce the structure illustrated in Fig. 11, i. e. before performing the additional machining operations shown in Fig. 12. In this modified procedure, after the :transverse grooves have been completed, this is followed by the machining steps shown in Fig. 12, resulting in the same structure as before, and which has been described with reference to Fig. 13. 7

According to either of the procedures I have described, the final result will be substantially the same, and the form of the surface of the roll pass will be somewhat as illustrated in Figs. 14 and 15. Of course it will be appreciated that this form is subject to considerable variation in accordance with the design of the particular reinforcing bar which it is desired to produce, as my apparatus is not limited for use with any one particular design of bar. 7

Other features of my invention are illustrated in Figs. 3 and 4 which reveal in somewhat greater detail the form of the cutter itself. In my preferred form of apparatus, I employ a cutter in which the cutting teeth 2| are of carbide. These teeth may be formed integrally with a carbide shaft section 66 suitably secured to the main sections of shaft l8, as by means of silver solder. Also they may be joined by a tongue and groove section as shown. However this does not form any part of my invention, and is merely referred to for completeness. I have found that best results are obtained if the angle of the cutting face 67 of the teeth 2i is disposed at a slight angle to a true radial direction as indicated at a in Fig. 3. This angle, for example, may be 5. Also I have had good results by arranging the faces 61 of the teeth 2! at an angle to the longitudinal axis of the cutter shaft as shown in Fig. 4.

In Figs. 7 and 8 I have illustrated one possible modification of the cutter assembly in which the bearing for cutter shaft 68 is formed in part by adjustable blocks 69 slidably mounted in complementary recesses IEI formed in plates H and 12. Bearing blocks 69 are arranged in close proximity to the teeth 2| of the cutter so as to afford an adjustable support for the shaft 68 where there is likelihood of the greatest amount of wear due to the fact that the pressure is at a maximum at these points, and due to the accumulation of chips or for other reasons. Adjustment'of blocks 69 is accomplished by means of screws 13 which have threaded engagement in plates H and 12 with their ends bearing against the ends of the blocks. These screws are held in the desired position of adjustment by means of lock nuts 14. As wear occurs, these nuts can be backed off slightly and the screws 13 taken up sufficiently to compensate for the wear. In other respects this form of cutter is substantially the same as the one previously described except for a different arrangement of the dowel pins and clamping screws, but these details can be understood from the drawings without detailed explanation. The connection between the cutter shaft 68 and spindle is modified somewhat, being formed by an axial bore H3 and an adjacent transverse slot H. The enlarged end 18 of shaft 68 is provided with flattened end portions 15 for engagement with the sides of transverse slot 11, thereby providing a driving connection between the spindle and the shaft. A collar 80 fixed to the other end of shaft 58 as by means of a pin 81 provides a thrust bearing against the recess 82 in the plates H and 2. The sides of plates H and I2 adjacent the recess therein preferably are bevelled as shown at 83 to afford additional clearance and avoid interference with the sides of circumferential grooves I7 during the machining operation.

The terms and expressions which I have employed are used in a descriptive and not a limiting sense, and I have no intention of excluding such equivalents of the invention described, or of portions thereof, as fall within the purview of the claims.

I claim:

1. In apparatus for the manufacture of steel reinforcing bar for concrete structures and the like, a machine unit for producing transverse grooves Within circumferential grooves of a bar rolling mill roll; which comprises a cutter shaft and a supporting bearing member therefor, the bearing member having separable parts with portions of the shaft bearing formed in each part, and bearing portions of said bearing member having direct engagement with the shaft around a portion of, its circumference at each side of and immediately adjacent the cutter and having direct engagement with the shaft around its entire circumference at points spaced some distance from the cutter.

2. In apparatus for the manufacture of steel reinforcing bar for concrete structures and the like, a machine unit for producing transverse grooveswithin circumferential grooves of a bar rolling mill roll, which comprises a cutter shaft and a supporting bearing member therefor, the bearing member having a recess therein of generally arcuate form, and cutting teeth on said shaft, the shaft being positioned in the bearing member adjacent said recess therein to expose the cutting teeth and part of the shaft, and bearing portions of said bearing member having direct engagement with the shaft around a portion of its circumference at each side of and immediately adjacent the cutting teeth and having direct engagement with the shaft around its entire circumference at points spaced some distance from the cutting teeth.

3. Apparatus in accordance with claim 2, in which the bearing member comprises adjustable elements mounted near the cutting teeth, said elements being adjustable transversely in relation to the shaft, and portions of the bearing surfaces for the shaft being formed in said adjustable elements.

4. In apparatus for the manufacture of steel reinforcing bar for concrete structures and the like, a machine unit for producing transverse grooves within circumferential grooves of a bar rolling mill roll, which comprises a long slim shaft having a cuttin portion the root diameter of which closely approximates the diameter of said shaft, and a supporting bearing member having an arcuate surface directly intersecting the cylindrical surface of said shaft at each side of said cutting portion whereby said shaft is supported throughout substantially its entire length.

F'ULVIO DE FAZI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,927,946 Miller Sept. 26, 1933 2,476,211 Muller July 12, 1949 FOREIGN PATENTS Number Country Date 566,296 Great Britain Dec. 21, 1944 

